X00 Subfield $m - Medium of performance for music:

Subfield $m contains term(s) designating the medium of performance used in a uniform title for a work in a name/title heading.

Examples:

100  1#  $aBeethoven, Ludwig van,$d1770-1827.$tSonatas,$mpiano.$kSelections

400  1#  $aSpeer, Daniel,$d1636-1707.$tSonatas,$mcornetts (2), trombones (3),$rC major

Subfield $m is not used for medium of performance information in a title page title used in a name/title heading.

Examples:

100  1#  $aRies, Ferdinand,$d1784-1838.$tOctets,$mpiano, winds, strings,$nop. 128,$rA major

400  1#  $aRies, Ferdinand,$d1784-1838.$tOctet, opus 128, for piano, clarinet, horn, bassoon, violin, viola, cello & bass

100  1#  $aBeethoven, Ludwig van,$d1770-1827.$tPiano music.$kSelections

400  1#  $aBeethoven, Ludwig van,$d1770-1827.$tBagatelles, rondos and other shorter works for piano

[Title page title]

Multiple adjacent elements in a single medium of performance statement are contained in a single subfield $m.  Subfield $m is repeated only when medium of performance statements are separated by subelements contained in other subfields.

Example:

100  1#  $aArne, Thomas Augustine,$d1710-1778.$tConcertos,$mkeyboard instrument, orchestra.$nNo. 3,$pCon spirito,$mkeyboard instrument

[Subfield $m is repeated due to intervening subelements.]

If the uniform title includes as part of the medium the abbreviation "acc." or "unacc.," the abbreviation is recorded in subfield $m.  The abbreviation "unacc." is recorded in subfield $t when it is not an addition to a statement of medium.  When a phrase such as "pianos (2)," "4 hands," etc., follows a collective uniform title for a specific medium of performance, it is included in subfield $t.

Additional examples are under the descriptions of subfields $o and $r.